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Anything programming related to the Hexbright

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Efficiency with and without DPIN_DRV_MODE MOSFET

While writing some custom firmware for the HexBright, I came across the DPIN_DRV_MODE pin, which, as I gather, controls a MOSFET that supplies extra power to the LED. Thus, setting DPIN_DRV_EN to 255 without the MOSFET is medium light in the factory firmware, where 255 with the MOSFET enabled is full power.

In the fader demo, DPIN_DRV_MODE is left enabled and the value of DPIN_DRV_EN is the only thing changed. This results in a smooth fade.

However, my question is this. For identical brightness output with the MOSFET enabled or disabled (i.e. 255/Off vs. some lower value/On) is there any significant loss associated with using the MOSFET? The reason I ask is because I want to write smooth fading transitions but I don't want to lose efficiency/runtime on the low end by leaving DPIN_DRV_MODE enabled, and I don't have the equipment to test current draw.

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I don't know about power efficiencies, but max on low is equivalent to about 45-48 on high.

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It's not known. There is no current schematic available, contrary to the open source promises.

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I would say that you are more efficient if you use the lower setting (and an appropriately higher PWM value). At least that is what I can surmise based on observations with my light. The sense voltage is constant in either mode (and rather high on my light, at 275 mV!), set by the LM4040 and a resistor divider. Changing to low mode lowers the current in the LED, which makes it run at a higher efficiency. So it is better to run a higher efficiency at a higher duty cycle on the low setting. However, if you want an output that is more than you can get at 100% (DPIN_DRV_EN=255) for the low setting, you are forced to switch to the high setting.

The XM-L U2 LED is about 16% more efficient at 700 mA than it is at 1500 mA, assuming that the LED temperature is the same.

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Justin will be eternally grateful.
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